The present invention relates to an electrical connector for vehicles, in which a junction block (hereinafter abbreviated to "JB") and an electronic circuit unit (hereinafter abbreviated to "unit") are disengageably connected through connection between connectors.
2. DESCRIPTION OF RELATED ART
A plurality of JBs are in general used in the wiring of a wiring harness in a vehicle for the purpose of simplifying the wiring.
Such a JB generally comprises a main body and various electrical components such as connectors, relays and fuses at the ends of wires which are mounted on the main body. A typical JB also incorporates therein a bus bar through which electric circuits are connected in a branching manner. Recently, however, JBs have often been used in combination with units having various function circuits.
A unit of this type comprises a printed wiring board, various electronic components such as condensers, diodes, LSIs and ICs which are mounted on the board, and a casing accommodating these members and consisting of upper and lower parts. Some examples of function circuits of the type mentioned above are a circuit for producing a warning of a condition in which a seat belt is not fastened properly, a circuit for producing a warning of a condition in which a door is not fully closed, a wiper control circuit, and a defogger control circuit.
The connection between the JB and the unit has hitherto been attained by providing the JB with a connector enabling connection to the unit and the unit with a connector enabling connection to the JB, and bringing these connectors into fitting engagement with each other. The connector of the unit is constructed such that it does not project from a front face of the casing of the unit which forms a plane of reference for fitting the unit to engage with the JB. This arrangement is adopted for the following reasons. Since the connector of the unit is secured to the printed wiring board disposed inside the unit, if, conversely, the connector projects from the casing, the connector would be more vulnerable to external stresses to which it may be exposed during transportation and assembly of the unit, and there is a risk that the printed wiring board may be subjected to external forces that might cause deformation of the connection terminal, as well as formation of cracks at portions of the board where the circuits are soldered.
With this construction in which the connector of the unit is depressed from the fitting engagement reference plane toward the inside of the unit, the male terminal of the JB has to be provided in such a manner as to extend or rise from the bus bar toward the unit. The height of this extension increases to the same extent that the connector of the unit is depressed from the fitting engagement reference plane.
Thus, such a conventional arrangement for attaining connection between the JB and the unit necessitates maintaining a dimension sufficient for the height of the extension of the male terminal of the JB. This requirement, in turn, results in certain limitations on possible arrangements of the bus bar with respect to the circuits. Consequently, design and manufacture of the bus bar is difficult and the male terminal may not be well arranged, either. In this way, the conventional arrangement fails to guarantee a level of quality sufficient to ensure that stable electrical connection is provided between the JB and the unit.